Adapter



5 1929. Feb H. c. DRAKE ADAPTER v A Filed Dc. 19, 1924 El] :l:

referentes rei. s, ieee.

garant carica.

HARCOURT C. BRAKE, 0F HEMPS'IEAD, NEW YORK, ASSIGNOR T0 THE SPERRY GYRO- SCOPE COMPANY, OF BROOKLYN, NEW'YORK, A CORPORATION OF NEWYORK.

ADAPTER.

Application med December is, i924. \ser iai No. 757,123.

This invention relates to adapters especially designed for use in the radio art. More particularly this invention relatesto adapters designed to permit the use of a plurality of different types of appliances within the standardsockets now provided in radio receiving instruments. These 'adapters are particularly designed to receive audion bulbs of various 'types and designs. Thus, for eX- ample, this invention has for one of. its o bjects the provision of an adapter Which will permit audion bulbs having various sized bases to be employed in connection with the ordinary sized sockets now utilized in radio receiving sets. Further, this invention has for its object the provision of adapters permitting the use of various types of audion bulbs other than the ordinary type bulbs now in use andwhich employ a battery to supply l). C. current for heating Jthe vilament. Thus, for example, my invention provides an adapter which will permit the use in the present type of socketof al type of audion bulb adapted to utilize the household circuit for heating the filament.

Further, this invention contemplates the provision of adapters for use with screwbase type audion bulbs as well as adapters for use with bayonet type bulbs.

The advantages of an adapter of this type will be readily apparent since sockets for receiving the'audion bulbs are built into receiving sets in a very substantial manner and, especially in the high priced sets7 cannot be removed except atgreat expense and at the danger of damage to the set.

While I have attempted to indicate some of the uses of ihy invention in the preceding paragraphs, it will become apparent in the following descri )tion that other uses and advantages thereo will readily be found.

In the accompanying drawings.

Fig. 1 is a vertical section through one form of adapter embodying my invention and showing said adapter applied to the ordinary type socket and supporting a screwbase type audion bulb.

Fig. 2 is a View similar to Fig. l but showing another form of my adapter designed to support abayonet type audion bulb.

Fig. 3 is a plan View looking down on the adapter which I ein loy in Fig. 2, the bulb i having been remove I Fig. 4 is a view looking up at the bottom of the adapter which I employ in Fig. 2.

to theheating element through said adapter.

Fig. 7 is another form of adapter which may embody the features of either the Fig. 1 or Fig. 2 device and showing the method of accommodating audion bulbs having bases of various sizes Within a socket of standard' size.

My invention can best be described by re1- ferring first to the present type of audion bulb which may be the standard De Forest bulb andthe present type of socket for receiving said bulb.

The present audion bulb has lfour prongs and fits into a socket'having four leaf springs with which the four prongs contact. Two prongs connect with the two ends of the cathode or filament and are in turn connected through two of the leaf springs to the terminals of a D. C. source of current, such as a battery. A third prong connects with the plate and through another leaf spring in the socket engages a source of D. C. current, known as the B battery. The fourth prong connects with the grid and the'leaf spring of the socket'which it engages is connected in circuit with a transformer or tuning unit or is otherwise connected in' a receiving circuit.

When, however, an audion bulb of different type is employed, especially those new types of bulbs which employ a filament or heating element separate from the cathode and utilize a source of current other than `a. battery for heating the filament, it is quite apparent that the present socket cannot be em-A ployed because the leaf springs or contacts thereof which engage the" filament orheating element cannot be connected to a source of current other than a battery, otherwisea hum will be set up in the circuitidueto com-- mutator ripple or A. C. period. One form of. such audion bulb is shown at 1() in Fig. 1 and comprises a' plate 11, a grid 12, a cathode 13, whichcorresponds'to the filament inthe old type, and a separate heating element or filament 14 for heating said cathode. Said-heating element 14 is 'supica l plied from a source of current of relatively high voltage and said source may beY the ordnary household' circuit either A. C. or D. C.

Since the heatin filament 1n this case4 is not in the receiving circuit the latter will not be affected by commutator ripple or A. C. period due to lthe source of current supply.

In the type of bulb shown in Fig. 1 the' plate, grid and cathodeare connected by wires 11', 12', 13,.which extend outside of the bulb and may be led to the various points, of connection.

It is apparent that if this type of bulb 10 is employed, three spring contacts 15, 16, 17 of the ordinary socket 20, such as is employed in standard receiving sets, may be connected to the three lines 11', 12', 13' but that separate connections are necessar for the heating element or filament 14. ne form of my adapter makes provision for all of these features. `This adapter is shown at A and fits directly into the socket 20 and is located therein by means of a bayonet lock which includes the pin 21 and the slot 22, one on the adapter and the other in the socket.' Said adapter has embedded therein three conductor lines 11,", 12 and 13" which terminate on the outside of the adapter in terminals 111, 121, 131. Also embedded in-said adapter A are twoconducting lines 23, 24 terminating invterminals 23', 24' on the outside thereof, said lines 23, 24 terminating one in a post 25in the bottom' of the adapter and the other yin a contact on the inner wall thereof. The

and terminating in a contact 26 and the other terminal extending to the side of the base -and connecting at27 to the conducting side walls of the base. It is apparent that when lthe bulb 10 is inserted within the adapter,

either'longitudinally,.if the base is a plain cylinder, or by screw threading, if it is of the type shown in Fig. 1, that the contact 2 6 will engage contact 25 and contact 27 will be in lengagement withconductor 24 so that by n connecting terminals 23', 24". to a suitable er merel source of current, which may be the household circuitthe heating element 14 will be ener ized. t the same time the plate, grid, and lament connections l1', 12 and 13 connectingwith the terminals 111,1121 and 131 will be connected in the receiving circuit by contacting with leaf springs 15, I16, 17. If desired a fourth, but dead or inactive, rong 18 may be `provided to engage the fourt contact s ring of the socket in order to support thea apter A. at all points and balance the same.

Another form of my adapter is illustrated in Fig.`2 and is designated Af. lThis adapter is designed especially foruse with'the bayonet type A. C. audion bulbwhich is inserted into the socket, or in this case into the adaptby a linear movement. The

adapter is inserted in the socket 20 in a manner similar to the adapter A. thisy case, however, the bulb 10 is provided with five conducting lines corresponding to '11', 12', 1-3', 14', 14", which extend straight downwardly into the base and not through the glass wall thereof; Upon the bottom of the base is provided five prongs connected two prongs must make contact with terminals leading to a suitable source of current.

'For this purpose the adapter A is provided with three conducting receptacles 31, 32, 33 adapted to receive the three prongs marked P, Gr and C, for the pla'te, grid and cathode,

respectively, said receptacles 31, 32, 33 having extensions extending through the base of the adapter A' and engaging the .leaf spring contacts 15, 16 and 17 respectively of the socket 20.

As shown in Fig.6 the remaining two prongs I-I', H" connected to the conductors 14', 14" ofthe heating filament also enter receptacles34, 35 fixed in thebase of the adapter A', but these receptacles 34, 35 do not extend through the base of the adapter as in the case of5 the other receptacles but connect with` conductors 36, 37'leading to the terminals 38, 39 on the outside of the adapter so that said heating Aelement can be connected to a suitable source of current, preferably a high voltage source such as the household circuit.

In this case also fouiprongs extend down- Ilm Wardly from the bottom ofthe adapter as shown in Fig.' 4 for enga in the four ron s of the socket.-v In'thisy las also onepprolg may be a dead prong merely for the purpose of providing an additional point of support for the adapter or it may be connected to the prong which forms the extension of a receptacle 33 which extendsv through the base of the adapter and engages the cathode prong C. This arrangement is desirable because in some circuits the leaf spring 17 which is ordinarily connected to one terminal of the cathode, may be the one in circuit or it may be the fourthy leaf spring, not shown, and which of the cathode that is in circuit. In the latter -is ordinarily connected to the other terminal case, if the dead prong C were not connected t mits bulbs of the type which require a difi ferent source of current than those normally used `in the ordinary receiving circuits to be employed in connection with the ordinary type socket at present in said sets. The adapter is also serviceable in permitting the use of bulbs having bases of various sizes either smaller or larger than the standard sockets 20 permit. Thus the ordinary D. C. type bulb ma be provided with a base that is smaller or arger than the said socket or the types of bulbs described in Figs. l'and 2 may be provided with bases of smaller lor larger sizes than the said socket. My adapter can very easily be so formed as to take care of this contingency either alone or in connection with the featurealready described of permitting some'different source of current.

Fig. 7 illustrates one manner of taking care of various sized bases. This consists merely in shaping the adapter with a lower portionwhich lits into the socket and provided with an opening or receptacle of the size adapted to cooperate with .the particular base of the audion bulb used.

In accordance with the provisions of the Having described my invention, what I claim and desire to secure by Letters Patent 1s:

1. An adapter for audion tubes having a plate, a grid, a cathode, and a heater element for said cathode, said adapter having means in its base for effecting connections to said plate, grid and cathode and having means in its side Wall for eecting connections to said heater element.

2. An adapter for audion tubes having a plate, a grid, a cathode, a heater element for said cathode, and five leads connected to the foregoingtube parts and projecting from said tube, said adapter having a plurality of receptacles in its base for receiving the terminals of said leads, the receptacles connected to said plate, grid and cathode extend? ing through the base of said adapter, said adapter having connections in the side walls thereof connected to the remaining recep tacl'es'containing the heater element leads.

3. An adapter for audion tubes'having a plate, a grid, a cathode, a heater element for said cathode, and tive leads connected to the foregoing tube parts and projecting from said tube, said adapter having a plurality of. receptacles in its base for receiving the terminals of said leads, the receptacles connected to said plate, grid and cathode extending through the base of said adapter to form prongs on the lower surface thereof, and an additional prong on the lower surface ofsaid base, said adapter having connections in the side walls thereof connected to the remaining receptacles containing the heater element leads.

In testimony whereof I have aiiixed my signature.

HARCOURT C. BRAKE. 

